Understand better the patent opposition

After the grant of a European patent, within nine months, an opposition can be filed with the European Patent Office (EPO) against the patent by any third party (in general, they are competitors of the patent owner) in order to obtain the invalidity or limitation of the patent, on a centralized and retroactive basis. The opposition targets all the designated States.


Opposition can be based on one of the following grounds:

  • The subject matter of the patent is not patentable (lack of novelty or inventive step for example)
  • The invention is not described clearly and completely enough for a person skilled in the art to be able to carry it out (insufficient description)
  • The subject of the granted patent goes beyond the content of the application as filed.


Thus, any third party can initiate opposition proceedings against your patent if they deem it necessary. You have this same possibility in the event one of your competitors files a patent that falls within one of the previous cases.

Since the PACTE law, the patent opposition procedure is also available in France and you can contest all or part of a patent filed with the INPI (National Institute of Intellectual Property), without having to file a lawsuit.


At the end of the proceedings, the patent is either:

  • Maintained as delivered, the opposition is then rejected;
  • Maintained in a modified form;
  • Revoked, totally or partially.


Understand better the patent opposition

Be accompanied in your project by an expert

Opposition is a major challenge in the life of a European or French patent and from a strategic point of view, both for the owner and all competing companies. It is a complex and highly formal procedure which requires both a technical and intellectual property knowledge, especially patent law. This is the reason why it is strongly recommended to call on the expertise of patent attorneys authorized before the EPO or the INPI as are the patent attorneys of Brandon IP.

Indeed, the filing of an opposition must meet very strict conditions and may be declared inadmissible on the grounds of a technical problem or failure to meet a deadline, for example.

Our patent attorneys authorized before the European and French Offices, are qualified to support you, advise you and represent you at each stage of this procedure, whether in the defense of your patent or to oppose a patent from a third party.

Experts in intellectual property close to you and your needs

Since 1866, Brandon IP, formerly known as Blétry Frères, has supported its clients in the protection and defense of their intellectual property rights. It is one of the oldest intellectual property firms in France. We support project holders and companies of all sizes in the protection of their creations in an individually adjusted way and as closely as possible to their needs. As a guarantee of our expertise, Brandon IP is ranked among the best French IP law firms by Décideurs Magazine (Leaders League).

Our patent team is composed of patent and trademark attorneys, experts in different technical fields, and of legal assistants. The engineers are in charge of consulting, studies, prior art searches, drafting of patent applications, etc. The paralegals are responsible for managing deadlines, contact with the various Offices, etc.

Meet our team here:

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To know more about our services, contact our IP teams.


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